1.1. Is a short letter enclosing the required catalogues and price-lists, a brochure, etc. Some 'sales talk', such as 'We are sure our high-quality products will meet your requirements, and we are looking forward to your early order' is generally included.
2. The Enquiry (Inquiry) Letter
2.1. You send an inquiry when you wish to have some information on a product or its sale (after you have seen the product advertised, or displayed at a fair or exhibition, or you have only heard about it).
3. The Letter of Complaint
3.1. Is sent by the customer when after receiving the goods he finds that they are not up to order. They may be of the wrong size or colour, their quality might be inferior, there might be a shortage of quantity or weight, etc. When you have a complaint, you relay this information in a professional and ethical manner to the person you have the problem with.
4. The Letter of Apology
4.1. Is a reply to the letter of complaint. The Letter of Apology should be courteous, even if the complainant has abused you. You should be truthful – if you have already been having trouble with the product, say so. Try to sound sincere, and, where necessary, be prepared to take full responsibility.